Improvement in direct-acting engines



W. F. GARRISON. Direct-Acting Engine.

Patented April 1,1879.

zl ezztar Mbmsses v IPETERS. PIIOTD-UTHOGRAFHER, WASHINGTON, D C.

UNITED STATES PATENT OFFICE.

WILLIAM F. GARRISON, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN DIRECT-ACTING ENGINES.

Specification forming part of Letters Patent No. 213,890, dated April 1,1879 appication filed August 23, 1878.

To all whom it may concern:

Be it known that I, WILLIAM F. GARRISON, of the city of Brooklyn, in thecounty of Kings and State of New York, have invented a new and usefulImprovement in Direct-Actin g Engines for Operating Air and GasCompressors, and for other purposes, of which the following is adescription, reference being had to the accompanying drawings, formingpart of this specification.

This invention more particularly relates to direct-acting steam-enginesin which the resistance to be overcome is a gradually-increasin g onefrom the commencement of the stroke of the en gine-piston in eitherdirection to the close thereof-as, for instance, when the engine is usedto work an air or gas compressor by the direct connection of the pistonof the latter with the piston of the engine.

The object of the invention is to provide, in a simple manner, for theregulation of the supply of steam to the engine-cylinder during thewhole of its stroke in such manner that the pressure of steam upon saidpiston may throughout the whole stroke be approximately in proportion tothe gradually-increasing resistance of the work-that is to say, in theapplication of the invention to driving an air or gas compre'ssor,ashereinbefore referred to, that as the resistance to thecompressor-piston increases from the commencement to the termination ofits stroke, the pressure of the steam on the engine-piston may becorrespondingly increased.

To this end, whether the invention be applied to Working an air and gascompressor, as described, or to the performance of any other work inwhich the resistance to the engine-piston is a gradually-increasin g onethroughout the stroke of said piston, the invention consists inproviding in the steam-passages, between the induction and eductionvalve or valves and the ends of the bore of the steam-cylinder, twoindependent valves, one for each end of the said cylinder, and in sooperating the said independent valves that as the piston moves towardeither end of the cylinder a contraction of the opening of theindependent valve belonging to that end of the cylinder takes place, andas the piston moves away from either end of the cylinder the said valveis gradually opened wider during such movement, thus insuring a moreregular movement of the piston. Such independent valves, it will beobserved, operate in a reverse or to tally diflerent manner to merecut-01f valves in the steam-passages of an engine for giving anincreased supply of steam at starting, and cutting it off. at any pointin the stroke as the piston advances, which valves, in connection withadditional exhaust-passages, have before been used for such purpose, andcoupled to control the passages leading to opposite ends of theengine-cylinder; but the independent valves in my invention have atotally different function, do not require separate or additionalexhaust-passages, and gradually increase their opening action to thesupply as the piston advances, thereby forming what may be termedincreasing-supply valves.

In the accompanying drawings, Figure 1 is a side elevation of adirect-acting steam-engine having my invention applied, and showing saidengine in connection with an air or gas compressor, illustrating theaction and utility of the invention; but such compressor forms no partof this invention. Fig. 2 is a longitudinal section of the same.

A is the steam-cylinder, and B the main slide-valve, for induction andeduction of the steam to and from opposite ends of the said cylinderthrough the passages cm. This valve may be of any well-known or suitableconstruction, the ports in its seat communicating with the passages a a,being laid out and arranged to suit the construction of the valve, whichmay be also operated in any well-known or suitable manner, either by theaid of a supplementary valve and piston, or of any other means actuatedby the rock-shaft 0, whose arm D derives motion from the piston-rod D.

c c are the independent valves, which constitute the principal featureof the invention, arranged in the passages on a, between the maininduction and eduction valve A and the bore of the cylinder. Thesevalves 0 c are represented of cock-like construction, consisting ofplugs having transverse passages through them, and fitted into seats dd, which intersect the passages a a. The spindles of the said valves arefurnished with arms I) b, which are both connected, by a rod, 0, withthe operating-arm D of the induction and eduction valve-gear, as shownin Fig. 1, in such manner that as the piston moves in either directionthe valve, cor c, belonging to that end of the cylinder from which thepiston is moving will have an opening movement, and the other one willhave a closing movement, the firstmentioned valve being opened wide asor only a little before the piston completes its stroke, and thelast-mentioned being at the same time nearly closed, or very muchcontracting the opening of its passage. This operation of the valveswill give only a small supply of steam and a light pressure on thepiston as the latter commences its stroke, and the resistance to themovement of the compressor-piston, or of the work whatever that may be,is slight, and will give a gradually-increasing supply of steam andincreasing pressure as the stroke of the piston progresses and theresistance to the compressor-piston increases by reason of thecompression of the air, thus obtaining a more regular movement of thepistons. This operation is independent of the action of the inductionand eduction valve or valves, which act in the usual way, and the saidoperation is eflected without cramping the exhaust, the valves 0 0 beingwide open when the exhaust commences, and contracted prior to theiradmission of steam. These valves 0 c, by their action, form thehereinbefore-reterred-to increasing-supply valves. 7

In order to provide for giving a greater or less supply of steamthroughout the stroke of the piston, the valve-seats (l d are not formeddirectly in the cylinder A and passages a a, but consist, as shown inFig. 2, of separate tubes, having ports in them corresponding in sizewith the passages a a. By adjusting these tubular seats so as to bringtheir ports directly opposite the passages a a, the fullest supply ofsteam is obtained, and by turning or adjusting the said seats more orless out of line with the passages the latter are more or lesscontracted to more orless reduce the supply of steam, as may be desired,according to the work to be performed.

It is obvious that the invention may be applied to an engine for workinga vacuumpump with the same advantages as to an engine for working an airor gas compressor, 1nasmuch as in both cases the resistance to theengine-piston throughout its stroke is a gradually-increasing one.

I claim- 1. In combination with the cylinder, induction and eductionvalve or valves, and valvegear of a direct-acting steam-engine,independent increasing-supply valves, arranged, substantially as hereindescribed, within the passages between said induction and eduction valveor valves and the bore of the cylinder, and operated by the valve-gearto produce the contraction of the opening of said passages prior to theadmission of steam to the cylinder, and the wider opening of saidpassages as the stroke of the piston produced by such admissionproceeds, substantially as herein set forth.

2. The adjustable tubular valve-seats d d, having ports in their sides,in combination with the valves 0 of and the steam ways or passages a aof the engine, constructed and arranged for operationesseutiallyasdesclihed.

WM. F. GARRISON.

Witnesses:

HENRY '1. BROWN, T. J. KEANE.

